'I wouldn't like Sasha Fierce if I met her off stage', said singer Beyonce Knowles of her alter ego.

'She's too aggressive, too strong, too sassy, too sexy! I'm not like her in real life at all. I'm not flirtatious and super-confident and fearless like her.'

According to some experts, we are all schizophrenic to some degree – harbouring a little crowd of personal alter-egos to help us along our way.

I like the idea of recognising these characters, even if we don't go so far as naming them. Often dressing in a certain way – for work, for example – helps us to dial into certain aspects of ourselves.